1. Field
The invention relates to a display device, and more particularly, to a repairable display device.
2. Description of the Related Art
Display devices are devices visually presenting data. Examples of display devices may include a liquid crystal display (LCD) device, an electrophoretic display (EPD) device, an organic light-emitting display device, an inorganic electroluminescent (EL) display device, a field emission display (FED) device, a surface-conduction electron-emitter display (SED) device, a plasma display device, and a cathode ray tube (CRT) display device.
In particular, the organic light-emitting display device is a type of display device which displays image or text data by using light generated in response to holes from an anode electrode and electrons from a cathode electrode being combined together in an organic layer between the anode electrode and the cathode electrode.
Display devices may be classified into a passive matrix display device and an active matrix display device according to a driving method of an N×M matrix of pixels thereof. The active matrix display device may consume less power than the passive matrix display device, and is thus more suitable than the passive matrix display device for the realization of a large-size display. Also, the active matrix display device may provide a higher resolution than the passive matrix display device. The active matrix display device includes pixel driving circuits connected to liquid crystal capacitors or LEDs.
Each pixel driving circuit includes a thin-film transistor (TFT) and a capacitor. In an LCD device or an organic light-emitting display device, defects may occur in pixel driving circuits, i.e., in the TFTs or the capacitors of pixel driving circuits. A defect occurring in a pixel driving circuit, or in the LED or the liquid crystal capacitor connected to the pixel driving circuit, may cause a dark- or bright-spot defect. Pixel defects caused by defective pixel driving circuits are generally difficult to locate with precision, and even if they could be located, it is almost impossible to repair them through the application of laser beams because pixel driving circuits are generally located deep inside the display device near the substrate. Therefore, in reality, it is very difficult to repair defective pixels caused by defects in pixel driving circuits.